added Laser few questions

[Koen Vissers]

Hi All,


I added a laser today, Opt laser 6w.
Its working with the breakout board from cnc drive shop Hdbb2.
So i took output 4 with the pwm signal.
So the laser works but I need to set him on and off manual.
For safety I put a key switch between power and laser when I turn the key the laser fired up...

So my 1st question is

Can I take also output 4 for sending the signal to a relay to put the laser on and off?
4 screws there 2 for pwm and 2 for output
I dont think I can put direct on the output???
laser needs 12v 2amp, but is the power from the output strong enough for the relay??

2th question

When the program started (from the plugin) laser works fine but the spindle starts also???
Spindle is on/off normaly via modbus plugin.
I already set the M3 start on function off on the software
Should I make a new profile for using the laser.

Sory maybe stupid questions but its all new for me.

Thx already for your time and patience

Koen

[cncdrive]

Koen,

Everything depends on what do you want to do with the laser.
If you just want to switch it on when you start cutting and off when finished then a relay should work fine.
But if you want to modulate the laser, if the laser controller has a so called "TTL modulation input" and you want to modulate the laser to make engravings or just to tune down the avarage power of the laser then ofcourse a realy will not work for that, a relay would be too slow for that.

The HDBB2 isolated outputs are not too optimal to pass the laser PWM through and this is because the PWM is fast,
has a 100kHz base frequency with a 8bits resolution, so if you want to pass this signal through an optoisolator without distorsion of the signal then you need 25.5MHz digital bandwidth from the optocoupler.
The HDBB2 optocouplers are factors slower than that, the cut frequency is around 30-40kHz.
There are not many optocouplers which could throughput 25.5MHz signal without distorsion and this is why that these diode laser controllers are connected directly without isolation in most setups.
So, the best is if you will use a step or dir signal pin from the RJ45 connectors of an unused axis as the laser PWM if you want to modulate the laser. Those signals are not isolated.
Then you can connect that pin to the TTL/PWM input of the laser driver and pin 3. is the ground for that.

Answering the second part of your question:

To drive the fast syncronous laser output you have to use the M10/M11 commands. These commands acts in syncron with the motion buffer, so they generate the on/off signals without any delays to the movements, the signals are timed precisely.
And the M3 is an enable signal for the laser, so you first have to enable the M3 for the M10 to work.
So, if your spindle is controlled with M3 commands and if it only requires the start signal then your spindle will start, because you have to switch the M3 on for the M10 to work.

A solution could be to set the spindle speed to 0 before M3 or to connect/switch the power from the spindle off when you using the laser or to make a separate profile for the laser as you mentioned.

[Koen Vissers]

First a big thank you for all the anwsers.


What I want to do is both, engraving pictures, as lazering vector files. So I think I go the second way.
BUT again a problem , I already has 4 axis used xyz and rortary.
So correct me if Im wrong. I use the 400 serie with two ports, I order a second breakout board and plug it in the second port.

Or is there a board outside where I can plug in 5 axis??? please recommend.


Second question , I will go the way of a second profile, now I understand it a litle bit.
English isnt so easy always to understand but we learn every day.

Thx again



Koen

[cncdrive]

OK, if you want to engrave pictures that crosses out the possibility to use a relay as the switching device, because picture engraving requires high speed switching.
Just imagine that the PWM has a 100kHz carrier frequency which means that the signal can change state 100 000 times per second. Ofcourse a relay can't switch that fast.

If you already using all 4 axis on the breakout board and you only need to add the laser PWM signal in addition to that then you could simply use the signal directly from the 2nd port of the UC400ETH.
Connecting the step or dir signals from the RJ45 jack of the axis connectors is exactly the same as if connecting directly to an output pin on the motion controller, because these signals are not isolated on the HDBB2 board. These signals are just passed through, because the stepper or servo drivers have optoisolator inputs anyways, so optoisolating these signals on the BOB is not required.
And because you need a distorsionless high frequency and high resolution signal to throughput my advice is to connect it directly without isolation.

[Koen Vissers]

Hi all


I wanna say a BIG THANK YOU for Cnc Drive for the exelent customer support.
Everything is working perfect.

Whitout the forum I would search for days to find the solution.

Thx Balazs :

[cncdrive]

Hi Koen,

You are welcome.
It is good to hear you had progress and got the laser working.

[laranja169]

Hello, and thanks a lot for this usefull forum and Software.

So I bought the same OptLaser 6w but i Have an CNC from Stepcraft, the Stepcraft D series 2/840.

I bought a DB15 connector to make the cable to connect the laser to my CNC and I use the UCCNC bought the license on Stepcraft too with the UC 100 controller.

Can you please help me config everything with UCCNC?

I use the Vectric softwares to make the Gcodes, can someone help me finding a good postprocessor for Vectric? Iám using Stepcraft Laser postprocessor.

What i Found about wiring:

PIN 13- Laser +
PIN 2- Laser -

I read too that if I want/prefer PWM (what's this?)
PIN 7- Laser +
PIN 2- Laser -

Thanks a lot for every help that someone could give me in advance.

Greets from Portugal!

[cncdrive]

Hi,

I don't really know what the "I read too that if I want/prefer PWM (what's this?)" could possibly mean, I can only guess.
My guess is that the pin 13/2 is just an enable signal which makes the laser slowly responding, just switching the laser board on and off and the pins 7/2 is probably a signal for laser modulation with which you can control the laser avarage power with a PWM duty cycle.

The UCCNC can output a PWM for the laser for both cutting and engraving.
You should configure the laser output port and pin in the I/O setup in the configuration.
Then you can switch the laser on and off with a set PWM duty cycle using the M10 Q.. command where the Q can have a range of 0 to 255 value. The 0 is 0% duty cycle and 255 is 100% duty cycle and ofcourse the inbetween values are proportional duty cycles between the 0 and 100%.
And you can switch the laser off with M11.
One more thing is that the M10 to activate the laser you fist have to turn the M3 on for safety.

Also you can use the laser engrave plugin to engrave pictures. Just enable the plugin in the plugins configuration, load in a picture, set the parameters like the workpiece dimensions etc. and run it.

For post processor you will have to ask Stepcraft or Vactric, we do not have that unfortunately.